Thermal ablation is a main curative therapy for early-stage hepatocellular carcinoma (HCC). However, insufficient ablation has been shown to promote HCC progression. E3 ligases have been approved to play important roles in malignant tumors. Whether E3 ligases are involved in HCC progression caused by insufficient ablation remains unclear. Herein, using RNA-sequencing coupled with an in vitro loss-of-function screen, we found that the E3 ligase Neuronal Precursor cell-expressed Developmentally Downregulated 4 (Nedd4) was upregulated in HCC insufficient ablation tissues and promoted HCC cells migration. The upregulation of Nedd4 was induced by METTL14-mediated N⁶-methyladenosine modification after sublethal heat treatment. Knockdown of Nedd4 inhibited HCC metastasis and growth in vitro and in vivo. Mechanistically, Nedd4 enhanced TGF-β signal transduction mediated tumor progression by directly binding to TGF-β type I receptor (TGFBR1) and forming K27-linked ubiquitin at Lysine 391. Additionally, the adverse effect on HCC of sublethal heat treatment was mediated by Nedd4. Clinically, high Nedd4 expression was positively correlated with aggressive tumor phenotypes and poor prognosis in HCC patients. Patient-derived xenograft (PDX) model confirmed this conclusion. Collectively, this study demonstrated that Nedd4 induced by insufficient ablation plays a crucial role in promoting HCC progression and provides a novel therapeutic target for HCC.

热消融是早期肝细胞癌 (HCC) 的主要治疗方法。然而，已证明消融不充分会促进 HCC 进展。E3 连接酶已被证实在恶性肿瘤中发挥重要作用。E3 连接酶是否参与消融不充分引起的 HCC 进展仍不清楚。在此，使用 RNA 测序结合体外功能丧失筛选，我们发现 E3 连接酶神经元前体细胞表达的发育下调 4 (Nedd4) 在 HCC 不充分消融组织中上调并促进 HCC 细胞迁移。Nedd4 的上调是由 METTL14 介导的 N ^6诱导的-亚致死热处理后的甲基腺苷修饰。Nedd4 的敲低在体外和体内抑制 HCC 转移和生长。从机制上讲，Nedd4 通过直接结合 TGF-β I 型受体 (TGFBR1) 并在赖氨酸 391 处形成 K27 连接的泛素来增强 TGF-β 信号转导介导的肿瘤进展。此外，亚致死热处理对 HCC 的不利影响由 Nedd4 介导. 临床上，Nedd4 的高表达与 HCC 患者的侵袭性肿瘤表型和不良预后呈正相关。患者来源的异种移植 (PDX) 模型证实了这一结论。总的来说，这项研究表明，消融不充分诱导的 Nedd4 在促进 HCC 进展中起着至关重要的作用，并为 HCC 提供了新的治疗靶点。